package com.example.filter;

import com.alibaba.fastjson.JSON;
import com.example.common.BaseContent;
import com.example.common.R;
import com.example.domain.Employee;
import com.example.domain.User;

import com.github.xiaoymin.knife4j.spring.annotations.EnableKnife4j;
import com.sun.prism.impl.BaseContext;
import lombok.extern.slf4j.Slf4j;
import org.springframework.util.AntPathMatcher;
import springfox.documentation.swagger2.annotations.EnableSwagger2;

import javax.servlet.*;
import javax.servlet.annotation.WebFilter;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.IOException;

/**
 * 检查用户是否已经登录，拦截器
 */
@WebFilter(filterName = "loginCheckFilter", urlPatterns = "/*")
@Slf4j
public class LoginCheckFilter implements Filter {
    //路径匹配器，支持通配符
    public static final AntPathMatcher PATH_MATCHER = new AntPathMatcher();

    @Override
    public void doFilter(ServletRequest servletRequest, ServletResponse servletResponse, FilterChain filterChain) throws IOException, ServletException {
        HttpServletRequest request = (HttpServletRequest) servletRequest;
        HttpServletResponse response = (HttpServletResponse) servletResponse;

        //1. 进行uri的判断，诸如静态资源或者登里页面直接放行
        String requestURI = request.getRequestURI();
        log.info("请求的路径" + requestURI);
        //设置直接放行的请求路径
        String[] urls = new String[]{
                "/employee/login",
                "/employee/logout",
                "/backend/**",
                "/front/**",
                "/common/**",
                "/user/sendMsg",
                "/user/login",
                "/doc.html",
                "/webjars/**",
                "/swagger-resources",
                "/v2/api-docs"
        };

        //2. 而其他请求发现是否有session，有则放行，无则返回登录页面
        if (check(urls, requestURI)) {
            log.info("不需要拦截的请求路径" + requestURI);
            filterChain.doFilter(request, response);
            return;
        }


        if(request.getSession().getAttribute("employee") != null){
            log.info("用户已登录，用户id为：{}",request.getSession().getAttribute("employee"));

            Long employeeId = (Long) request.getSession().getAttribute("employee");
            BaseContent.setThreadLocal(employeeId);

            filterChain.doFilter(request,response);
            return;
        }

        //4-2、判断登录状态，如果已登录，则直接放行
        if(request.getSession().getAttribute("user") != null){
            log.info("用户已登录，用户id为：{}",request.getSession().getAttribute("user"));

            Long userId = (Long) request.getSession().getAttribute("user");
            BaseContent.setThreadLocal(userId);

            filterChain.doFilter(request,response);
            return;
        }

        log.info("用户未登录");
        //5、如果未登录则返回未登录结果，通过输出流方式向客户端页面响应数据
        response.getWriter().write(JSON.toJSONString(R.error("NOTLOGIN")));
        return;
    }

    /**
     * 进行路径匹配，如果包含该路径则返回true
     *
     * @param urls       所有路径
     * @param requestURI 目标路径
     * @return
     */
    public boolean check(String[] urls, String requestURI) {
        for (String url : urls) {
            boolean match = PATH_MATCHER.match(url, requestURI);
            if (match) {
                return true;
            }
        }
        return false;
    }
}
